Fluid-pressure-brake device



May 21, 1929. E. s. COOK FLUID PRESSURE BRAKE DEVICE Filed July 23, 1927 BY I ATTORNEY EARLE S.

nut zioq 33m :E I

Patented May 21, r

A UNITED STATES PAT NT l oF-Flcaqf ,EARLE s. 0001:, or WILMERDING, PENNsYLvAN A, ASSIGNOR THE WESTING- nous AIR BRAKE. COMPANY, or WILMEBDING, PENNSYLVANIA, a commaflIOIil' OF PENNSYLVANIA.

' FLUID-PRESSURE-BRAKE 'nnvi'cizr' Application filed July 23 1927. "Serial No. 207,839.

This invention relates to automatic train control apparatus and more particularly to that type having means for automatically effooting a brake pipe reduction intwo stages.

In the pending application of Thomas H. Thomas and Earle S. Cook, Serial No. 109,- 044, filed May 14, 1926, means are disclosed for automatically effecting a split or two stage reduction in brake pipe pressure, whenever the train control apparatus operates to inake a brake application on the train,

' \Vhether or not a two stage reduction in brake pipe pressure is required for applying the brakes on a train is mainly dependent upon the train speed. If the train speed is low, the retarding force on the train, caused by applying the brakes, develops much more rapidly than if the train speed is high, so that as a result, when the train speed is high, thebrakes may be applied by effecting a single and full reduction in brake pipe pressure,

without causing any damage to the train.

' The principal object-of my invention is to provide means for automatically causing a two stage reduction in brake pipe pressure'to be effected below a predetermined speed limit and for causing a continuous brakepipe re duction to'be efi'ected above a predetermined speed limit. T g

In the accompanying drawing, the single figure is a diagrammatic view'of a train con; trol apparatus embodying my invention.

As shown in the drawing, the apparatus may comprise a governor valve unit, a brake valve device 1, and asplit reduction valve device 2. r V I The construction and operation of the governor valveunit of this application is substantially the same as that of the construction disclosed in the Patent No. 1,553,603 of Clyde C. Farmer, granted September 15, 1925, while the construction and voperation of the brake valve device 1 and split reduction valve device 2 is substantially the same as that ofthe construction disclosed in the pending application of Thomas H. Thomas and Earle S. Cook, Serial'No. 109,044, filed May 14, 1926, and these devices therefore will not be described in detail, but onlyto the ex.- tent deemed necessaryto asfull and complete understanding of the invention. p

The governor valve unit comprises a governor portion3, a change speed valveportion 4, a timing portion 5, and a'magnet portion 6.

rThe governor portion 3 comprises a governor 7 of the usual centrifugal type, adapted to be rotated according to the speed of'the train and in operation isadapted to cause movement of a crosshead member 8, carrying a plurality of adjustable tappet' stems, adapted to operate corresponding valves at to I 7 various train speeds, said valves comprising governor speed valves 9, 10 and 11 and blow down timing valves 12 and 13.

The change speed valve portion 4 com prls'es'a casing containing a hlgh speed valve device and a--medium speed valve device.

The high speed valve device comprises a piston 14, contained in a chamber 15 andaslide valve 16 co'ntainedin a chamber 17 and adapted to be operated said piston. The

medium speed valve device comprises a piston 18, contained in a chamber 19 and afslide valve2O contained in the chamber 1 7,a nd

adapted to be operated by the piston 18 I v Thetiming portion5 comprises a casing containing a high'to medium speed'tim ing' valve device and amediumto low speed timingvalve device. Thehighto medium speed timing valve device comprises a diaphragm 21, subjecton one sideto the fluid pressure in a chamber 22 and on the opposite side to thepressure of-a coil spring 23, the diaphragm 21 being adapted vto operatea double beat'valve 24,contained in a valvechamber 25'. The-medium to low speed timing valve"device'comprises a diaphragm 26, subject on one side to the fluid pressure in a chamber 27- and on the oppositeside to the pressure of a coil spring 28, the diaphragm 26 being adapted to operate a valve 29 contained in a spring and valve chamber 30 and a'valve'31 contained in a spring and valve chamber 32. "The'magnetportion 6 comprises a high speed magnet valve device' 33 and a medium speed magnet valvedevice- 34}.- The high speed magnet valve -device33 comprises a magnet and valves 35 and36 operable by said magnet. .The. medium speed magnet valve device3t comprises a magnet and valves 37 and 38 operable by said magnet;

The bra'l're valve device 1 comprises'rotary valves 39 and 74 0, contained in a chamber41 and adapted to. be operated by a handle42, and the usual equalizing. piston mechanism, which comprises an equalizing vpiston 4 3, forming a chamber 44 at one side and a chamber at the opposite side, said piston being adapted to operate a brake pipe discharge valve 46. Said brake valve further comprises a cut-off valve 47, contained in a chamber 48, and carried by a stem secured to a piston l9, contained in a piston and spring chamber 50. Associated with the brake valve device is a brake application valve portion, which may comprise a piston 51, contained in a chamber 52 and a slide valve 53 contained in a chamber 54: and adapted to be operated by said piston. A spring 55, contained in chamber 52, opposes outward movement of said piston.

t The split reduction valve device 2 comprises a control valve portion and a holdback portion. The control valve portion comprises a piston 56, contained in a chamber 57 and a piston 58 contained in a chamber 59. Said pistons have different areas, are connected by a stem, and are adapted to operate a slide valve 60 contained in a chamber 61, formed intermediate said pistons. The hold-back portion comprises apiston 62, contained in a chamber 63 and a slide valve 6 1 contained in a chamber 65 and adapted to be operated by said piston. Inward movement of the piston 62 is opposed by a spring In operation fluid under pressure is supplied from a main reservoir 67 to the rotary valve chamber 41 of the brake valve device 1 and to the feed valve devices 68 and 69 through a pipe and passage 70. Fluid at the usual pressure carried in the brake pipe is supplied by the feed valve device 68 to the seat of the rotary valve 40 through pipe and passage 98, and with the brake valve device in running position, as shown in the drawing, said fluid flows from passage 98 through port 72 in the rotary valve 40 and passage to the cut-0E valve chamber 48 and to the seat of the application slide valve 53.

Fluid at the pressure employed in the operation of the train control apparatus is supplied by the feed valve device69 to the application valve chamber 54, to the .seat of the control slide valve 60 of the split reduction valve device, to the speed valve chamber 17 and the timing valve chamber 32 of the governor unit and tothe magnet valve chame bers 74 and 75, through pipe and passage 7 6 and from said passage 76 in the governor unit through a choked passage 77 and a passage and pipe 7 8 to the application piston chamber 52. Fluid under pressure also flows to said piston chamber 52 through a port 7 9 in the application piston 51. The fluid pressure thus equalizes on the opposite sides of the application piston 51 so that said piston and slide valve 53 are held in the release position, as shown in the drawing, by the pres sure of spring 55, in which position, cavity 133 in the slide valve connects passage 73 to passage 81 leading to the cut-off piston chamber 50, so that fluid at teed valve pressure is permitted to flow from passage 73 to the piston chamber 50 and act on the cut-oil piston 49 to open the cut-oil valve 47 and permit fluid under pressure to flow tothe brake pipe 82 and to the equalizing piston chamber #5 by way of passage Fluid at teed'valve pressure also supplied from the teed valve device 68 to theequalizing piston chamber 44 and to the equalizing reservoir 115 through passage 7 8, cavity 84: in the application slide valve 53 and passage the fluid pressurebecoines equal on the opposite sides of the equalizing piston -:land ensures seating of the discharge valve 46.

In territory governed by a high speed signal indication, the magnet ot the high speed magnet valve device 33 is energized and the magnet of the medium speed magnet valve device 34 is deenergized. 'With the high speed magnet energized, the valve is seat ed and the valve 36 is unseated, which per-' through port 87 inthe slide valve and passage 88 to a blow down reservoir 89 and to the diaphragm chamber 27 or the timing valve portion 5. The pressure in chamber 27 acts on the diaphragm 26 to seat the valve 29 and unseat'lthe valve 31. lVith the valve 31 unseated, fluid under pressure flows from the valve chamber to the medium speed piston chamber 19 by way of passage 90, and equalizcs therein with the pressure of the fluid in the valve chamber 17, and the pressure of a spring 91 then holds the medium speed piston 18 and slide valve 20 in the high speed position as shown in the drawing. lVith the medium speed slide valve 20 in the high speed position a timing reservoir 92 is vented to the atmosphere through pipe 93, through a ball check valve device 94, through pipe and passage 95, through a port 96in the medium speed slide valve 20, and through the atmospheric exhaust passage 97.

Nith the high speed slide valve 1.6 in the 85, so that ion lit

slide valve 60 in the normal position as shown in the drawing, in which, position, the holdback piston chamber 63 is ventedtotlie atmosphere through passage 101, cavity 102 in the control slide valve 60 and the atmospheric exhaust passage 134. Since the timing reservoir 92- is connected with passage 101 through pipe and. passage 103,,tl1rough the choked passage 104 and past the ball-check atmosphericpressure.

WVith the hold back piston chamber 63 vented to the atmosphere, the pressure of spring66 holds the hold-backpiston 62 and valve-105, SiilCl'lGSlVOiliiS also normally at slide valve 64in the outer position,in which,

a cavity-106 connects passages 107 and 108 leading to a first and a second reduction reservoir 109 and 110, respectively. Both of said reduction reservoirs are normally vented to the atmosphere, the first reduction reservoir through pipe and passage 107, cavity 111 down valves 12 and 13 are'held in their open positions i If thespeed of a train exceeds a predetermined high speed limit thehigh speed governor valve 11 is unseated byoperation of the governor .7 and thereby vents the appli-.

cation piston chamber 52 to the atmosphere through pipe and passage 78 andsaid unseated valve. The fluid pressure in the application valve chamber-.54 then. shifts the-application piston 51 and slide valve ,53 to the outward or application position, in which, cavity1111 in slide valve 53 connects passage 81. from the cut-ofi' piston chamber 50 to they atmosphere, through the exhaust passage 112 thereby venting the fluid from saidchamber and permitting the opposing pressure of the brake pipe fluid to shift the cut-off piston 49 outwardly and close the cut-off valve 47, so as to prevent further fiowof fiuidto the brake pipe 82. In application position of the application slide valve 53, cavity 84, therein, connects passage 85 from the equalizing res ervoir 115 and equalizing piston chamber 44 to passage 107 leading tot-he first reduction reservoir 109, so that the fluid under pres sure from the equalizing reservoir 115 and piston chamber 44 is permitted to flow to the first reduction reservoir and cause a pre determined decrease In the fluid pressure acting in chamber 44 upon the equalizing piston 43. Said equalizing piston then op brake pipe.

erates the discharge. valve/46 in thewell known manner to cause a corresponding decrease 1n the pressure of the fluid 1n; the

The fluid discharged from. the brake pipe past theivalve 46 and into passage 99is partially vented'to the atmosphere through the choke ,plug 100. Said chokelplug has less capacity than the opening'pastthe unseated discharge valve 46, so that a pressureis built up in passage and pipe '99 and'thecontrol piston chamber 57, which pressure, acting on the contr0l'piston-56, shifts-said piston and the piston 58 and slide valve 60-to adown wardjposition, in which, cavity 102 connects passage 7 6 from the feed Valve device 69v to,

passage 101 leading to the hold-back piston chamber 63.. Fluid at the pressure supplied by the feed valve device 69 thenfiows to the hold-back piston chamber and acts'to shift the. hold-back piston-62 and slide. valve 64 I to the inward position, in which the cavity 106 disconnects thepassages 107 and 108 leading to the first and second reduction reservoirs. Fluid at teed valve pressure from passage 101 also flows throughthechoked passage 104 and passage 103 to the timing reservoir 92. v i I v QlVith the trainin territory governedby a high-speed signal indication, themedium .7

speed piston-18 and slide valve 20 are main:

tained in. their innerposition, as hereinbe'- i fore 'described,1so that the fiuidunder pressure supplied to the timing reservoir 92 flows to the atmosphere through the port 96 in the medium speed-slide valve 20 and the atmosphericexhaust passage 97; Since the capacity of thechoked passagefl104 in the split reduction device is less: than the capacity of the exhaust from the timing reservoir 92, the timing reservoir is thereby maintained substantially at atmospheric.pressure.

When thebrake pipe pressure is reduceda degree corresponding substantially to the degree of firstreduction inequalizingreservoir pressure, the brake plpedischarge valve 46- starts to close and throttlehthe flow of fluid under pressure from the brake pipe I into the passage and pipe 99. When the rate of discharge pastthedischarge valve 46 thus becomes less than the venting capacity-oi the choke plug 100, the pressure in the control piston chamber 57 starts to reduce and when reduced to a predetermineddegree, the pressureof the brake pipe fluid in piston. chamber 59 shifts the control pistons 56 and 58 and slide valve 60 to th'eir'upper position, in which, the holdback piston chamber 63 is connected to the atmosphere thrOughpassage 1'01,'cavity 102 inthe control slide valve 60 and the atmospheric exhaust passage 134. The. pressure in the holdeback piston chamber 63 is thereby reduced almost instantly, so that the holdbackpiston 62 and slide valve 64 are shifted :to their outer position by the pressure of spring 66, in which position, the second reduction reservoir 110 is connected to the first reduc tion reservoir 109, and the fluid under pressure from the equalizing reservoir 115 and first reduction reservoir 109 is permitted to flow to the second reduction reservoir and eflect a second reduction in equalizing reservoir pres sure. The equalizing piston 43 then operates the discharge valve 46 to cause a further reduction in the pressure of the brake pipe fluid. It will :be noted that the discharge valve 46 does not fully close in order to permit the split reduction device to initiate the second reduction in equalizing reservoir pressure, so that as a result, the brake pipe reduction, caused by both the first and second reductions in equalizing reservoir pressure, is a continuous reduction.

During the second reduction, the holdback piston 62 and slide valve 64: of the split -reduction device are prevented from operat ing to again separate the two reduction reservoirsand thereby interfere with the second reduction, on account of the control pistons and slide valve being held in their upper position by the'pressure of fluid from a lock-up reservoir 116, which fluid is permitted to floW to the valve chamber 61 through passage 118 and port 117 in the control slide valve 60,

said lock-up reservoir becoming charged wvhilc effecting the first reduction, by fluid under pressure from the brake pipe, which fluid flows thereto through the passage 83 in the brake valve device 1, cavity 119 in the application slide valve 53, passage and pipe 120, cavity 121 in the control slide valve of the split reduction device and passage 118.

If itis desired to limit the degree of the second reduction in equalizing reservoir pressure to that required for effecting a full service application of the brakes, the brake valve device must be moved to lap position, in which position, the atmospheric connection of the second reduction reservoir, through the exhaust passage 11 1 in the brake valve device, is cut ofl. Under this condition, the degree of reduction is limited to the equalization of the fluid under pressure from the equalizing reservoir into the first and second reduction reservoirs; v

' If a train is running in high speed territory and the signal indication changes to amedium speed, the magnet of the high speed mag net valve device 33 becomes deenergized and the magnet of the medium speed magnet valve device 3 becomes energized. Deenergization of the high speed magnet permits valve 36 to seat and valve 35 to unseat, said latter valve thereby permitting the fluid under pressure in the high speed piston chamber 15 to be vented to the atmosphere. of the fluid in the valve chamber 17 then shifts the high speed piston 14 and slide valve 16 to the outward position, in Which, cavity 122 The pressure in said slide valve connects passage 123 from the high to medium blow down reservoir 12 1 and the diaphragm chamber 22 of the timing portion 5 to passage 125 lcadlng to the opened blew down valve 12. hen the fluid pressure acting on the diaphragm 21 is thereby plication of the brakes is initiated in the same manner as hereinbet'ore described.

In medium speed position of the high speed slide valve 16, cavity 126 therein connects passage 88 from the diaphragm chamber 27 of the timing portion 5 and from the medium to low blow down reservoir 89 to passage 127 leading to-the chamber 128 in the medium speed magnet valve device 34. P Since in medium speed territory the magnet of said device is energized, the valve 87 is seated and the valve 38 is unseated, which permits the flow of fluid under pressure from the valve chamber 4L to the diaphragm chamber 27 and the blow down reservoir 89, thereby maintaining the pressure on the diaphragm 26, so as to hold the valve 29 seated and the valve 31unseated, said latter valvejpermitting the fluid pressure to be maintained in the medium speed piston chamber 19. Thus, the medium speed'territory the medium speed piston 18 and slide valve 20 are n'laintained in their inner position, in which, the atmospheric connection of the timing reservoir 92 is maintained, which results in causing a, continuous brake pipe reduction to be eii'ected in the same manner as hereinbetore described.

If a train is running in medium speed territory and the signal indication changes to a 10W speed, the magnet. out the medium speed magnet valve device becomes deenergized and the high speed magnet remains deenergized. Deenergization oi the medium speed magnet permits valve 38 to seat and valve 37 to unseat, said latter valve thereby permitting the fluid under pressure from the diaphragm chamber 27 of the timing portion 5 and from the medium to low blow down reservoir 89 to be vented to the atmosphere past the open blow down valve 13. When the pressure acting on the diaphragm 26 is thus reduced a predetermined degree, the pressure of spring 28 deflects the diaphragm 26, thereby permitting valve'31 to seat and valve 29 to unseat, said latter valve thereby permitting the. fluid under pressure to be vented from the medium speed piston chamber 19 to the atmosphere, by Way of passage 90 and past said unseated valve. The fluid pressure 9 in valve chamber 17 then shifts the'medium speedpi'ston 18 and slide valve 20 to the outer position, in which, cavity 129 connects passa'ge'78' from the application piston chamher 52 to passage 130 leading to the] chamber containing the-low speed governor valve 10, which is open above the low speed limit;

a. ity' 131 to passage 80, which latter passage leads to the chamber containing themediuml speed governorvalve 9' and to the top of the 'ballcheck valve 132' in tlie'timing portion 5. Below the medium speed limit, the governor valve 9 is seated,.so that when the split reduction valve device 2 operates to supply fluid to the timing reservoir 92, the fluid from saidre'servoir flowsonly tot-he governor valve 9 and the ball check valve 132 and, as a result, a pressure is built up in the timing reservoir equal to the pressure in the l1old-back piston chamber 63. When the first reduction in brake pipe pressure is completed and the hold-back piston chamber 63 is connected to the atmosphere through the passa e 134, a period oftime is required to reduce the pressure in the hold-back piston chamber 63 to that. at which the spring 66 shifts the hold back piston and slidevalve 64 to the outward position, since the fluid from the timing reservoir 92 flows back to said piston chamber and must also be reduced. Therefore, a period of time elapses from the end of the first reduction in brake pipe pressure to the outward movement of the hold-back piston'62 and slide valve 64 and the consequent starting of the second reduction in equalizing reservoir pressure, so

that the brake pipe pressure istherefore reduced in two separate stageswith a tune interval elapsing between said two stages.

'If a tram 1s operatlng n territory gov-' erned by a high speed signalindi'cation and the indication changes to low speed, the medium speed piston 18 and slide valve 20 are shifted to the outward position, as just.

described above, butin this case, if the train speed is above a medium speed limit, the equalizing reservoir pressure is reduced in the same manner as when a brake application is effected by a change from a high speed to agmedium speed signal indication, as here inbefore described, because, above the medium speed limit the medium speed governor valve 9 is unseated, which provides an atmospheric vent from the timing reservoir 92 and hold-back piston chamber 63, thereby permitting the split reduction valve deviceto effect a continuous reduction in equalizing reservoir pressure. If, however, the train.

speed is below the medium speedjliniit and a' change from a high to a low signal indi cation occurs, asplit ortwo 'sta ge'reduction I is effected, sincefbelow themediu'm speed limit the. governor valve 9 is seated jso' that the fluid supplied to theftiming reservoir 92, by operation ot'th'e split reduction device during the first reduction, is not vented to the atm0sphere, but inste adiapressure is I built up in said timing reservoir to govern the time elapsingbetween the end 'of 'the first reduction'in brakepipe pressure and the start of the second 'red'uctionin saidpres sure, the same manner as hereinbefore described. I 1 1 r ""The'ball check valve device 94 is adapted to'prevent the'flow of fluid under pressure 1 from the governor unit to'the'timing reservoir 92. When an automatic"applicationof r the brakes occurs in territory governed by a medlum speed signal indicationand the medium speed piston, 18 and slide valve 20 are moved to the outward position, the cavity l 131 in said valveconnect's passage 80, leading I to the ball check valve l32, to the passage 95 leading to the timing reservoir 92, so that there would be a tendency for-the fluid sup- V plied to the application piston chamber52 of the brake valve device through port 79in 1 said piston, to flow through pipe and passage" 78, past the double beat valve 24, seated in its lower position, pastjthe ball check valve 132, through passage 80 to passage 95, and

from thence to the timing reservoir 72. This 7 would tend to maintain the pressure in the timing reservoir 92 and the hold-back pis-v ton chamber 63of the splitreduction'device and prevent the movement of the hold-back piston 62'and slide valve 64 to the outer position, as shownin the drawing, so as to start the second reduction in equalizing reservoir pressure. Introducing the ball check valve device 94 between the. pipes 93 and-95 pre vents the flow of fluid under pressure from passage 7 8 to thesplit reduction device and thereby prevents such undesired action.

Having now described my invention, what I Claim as W and esire to secure by Letters Patent,-is: 1

1. In a train control apparatus, the "compipe, of means for efbination with a brake fecting a'reduction in brake pipe pressure in two stages comprising a timing reservoir,

a valve device subject to the pressure of fluid in said reservoir and operativegto initiate the second reductlon 1n brakepipe pressure,

and a valve device operable according to the rolling the pressure signal indication for cont of fluid in said reservoir;

-'2. In a train control apparatus, the combination with a brake pipe, of means for effecting a reduction in brake pipe pressure in two stages comprising a timing reservoir, a valve device subject to the pressure of fluid in said reservoir and operative to initiate the secondreduction in brake pipe pressure, a speed controlled valve, a valve device having one position for connecting said reservoir to the atmosphere and another position for connecting said reservoir to said speed controlled valve, and signal controlled means for controlling the operationof said valve device. 7

3. Ina train control apparatus, the combination with a brake pipe, of means for effecting a reduction in brake pipe pressure in two stages comprising atiming reservoir,

a valve device subject to the pressure of fluid a valve device operated upon an increase and thena decrease in pressure in said reservoir for initiating the second reduction in brake pipe pressure, and means operated when the train is permitted to run at high speed for preventingan increase in pressure in said reservoir. V

a 5. In a train control apparatus, the combination with a brake pipe, of means for effecting a reduction in brake pipe pressure, a timing reservoir, a source of fluidrunder pressure, means operated during the period the brake pipe pressure is reducing for supplying fluid from said source to said reservoir, a valve device operated upon a predetermined reduction in. pressure in said res ervoir for effecting a second reduction in brake pipe pressure, and means controlled according to the signal indication for pre venting a substantial increase in pressure in said reservoir by flow from said source.

In testimony whereof I have hereunto set my hand.

EARLE S, COOK. 

